Electrical connectors generally include first and second connector bodies of moldable insulating material, with internal conductive terminals. The connector bodies are mated together with a push or slide fit, which causes the internal terminals to make electrical contact. The connector bodies must be fully mated to assure proper electrical contact, and, preferably, are somehow locked together to assure that contact is not broken. This is especially important in high vibration environments, such as automobiles, which could shake the connector bodies apart.
One common type of lock between matable connector bodies is the cantilever arm type. A flexible arm cantilevered to the first connector body has a forward end that slidably moves over a ramp, or under a bar, on the second connector body as the two are pushed together, locking them together. An example of such a lock may be seen in U.S. Pat. No. 4,010,998 to Tolnar et al, assigned to the assignee of the present invention. One potential problem with this type of lock is that the connector bodies may require some force in order to push them together, and unless they are fully mated, the forward end of the locking arm will not be fully engaged, nor, as a consequence, will the lock be fully engaged. There is no readily apparent indicator to inform an operator or assembler that the connector bodies are, or are not, fully mated. This is especially true in the cramped and sometimes blind assembly locations involved in automobile assembly. Another shortcoming is that the lock is a single lock only, with no back up or redundancy feature, and is subject to being released if the arm is flexed up or down, as it could be in a high vibration environment. Also, the cantilever arm is typically exposed and unprotected above the surface of the connector bodies.
A design that speaks to one of the problems noted above, the lock release problem, may be seen in U.S. Pat. No. 4,370,013 to Niitsu et al. A separate lock disabling means is snap fitted to the second connector body, and simultaneously moves beneath the cantilever arm on the first connector body to disable the locking arm from being released. However, the lock disabling means is effective only after the connector bodies are fully mated, and it fits to the second connector body regardless of whether the two connector bodies are fully mated. The lock disabling means in Niitsu neither assures that the connector bodies are fully mated, nor does it provide any indication of whether they are or are and would be difficult to apply in a blind or inaccessible location.